The species of polar bear (Ursus maritimus) is a descendant of the Grizzly Bear (Ursus arctos middendorffi). Appeared 130,000 years ago and has existed until now. But the evolution of the polar bear grizzly bear was not overnight. No went to bed grizzly and polar bear woke up, no. The change was gradual and evolutionary steps were perhaps different. One of them was the Ursus maritimus tyrannus, the Tyrant polar bear. As the name suggests, refers to a large bear, a tyrant as the famous T.Rex.

White Bear tyrant, was larger than its predecessor and its predecessor. We'll see

POLAR BEAR

SIZE: 3 METERS (10 FT.)
WEIGHT: 800-1000 KG ( 1950 - 2200 LB.)

POLAR BEAR TYRANNUS

SIZE: 3,5 METERS (12 FT.)WEIGHT: 1200-1400 KG (2100 - 2700 LB.)

GRIZZLY BEAR

SICE: 2,80 METERS (9 FT.)
WEIGHT: 750-1100 KG (1800 - 2050 LB.)

The bear tyrant was the first polar bear and evolved sometime in the Middle Pleistocene. It is believed that the species has evolved about 200,000 years ago from brown bear population which probably to remain insulated by glaciation. It is thought that the number of individuals of the species was scant and could not overcome the competition of species better adapted to the trust as the polar bear. Smaller, and able to feed on smaller creatures and more agile and specialized in ice cold weather and snow.

Although little is known about the diet of this prehistorical animal, it is thought that diet was more similar to the diet of the Grizzly, and therefore was developed as the last ice age, food became scarce, especially the vegetation and other (the polar) better adapted to cold, managed to survive and win the battle for the top of the food chain.